Flying cutter



Sept. 10, 1957 A; NOVICK 2,805,715

FLYING CUTTER Filed June 8, 1954 4 Sheets-Sheet 1 1 M INVENTOR.

22 Abraham A/or/ck ATTORNEYS FLYING CUTTER Abraham Novick Flushing N. Y. assignor to F. L. Smithe Machine (30., Inc New York, N. Y., a corporation of New Yor Application June 8, 1954, Serial No. 435,221 3 Claims. (Cl. 164-68) This invention relates to flying cutters, and more particularly to flying cutters used for the severing of successive rhombic envelope blanks, of various sizes, and at various selected angles, from a traveling web of paper. The present flying cutter is an improvement upon the flylng cutter disclosed in my pending application for Letters Patent of the United States, Serial No. 344,572, filed March 25, 1953, for Web Feed Envelope Machine.

The present flying cutter, although not limited in use to the cutting of envelope blanks, has been especially contrived with that use in mind, and will be illustratively described with reference to that use.

It is characteristic of a flying cutter of the prior art that a web is fed past a stationary cutter blade and that a rotary cutter blade, carried on a rotary support, is caused at each revolution to travel across the stationary blade and thereby to cut a definite length of material from the leading end of the web. In the flying cutter of Serial No. 344,572 the rotary cutter blade is desirably mounted square,.i. e., with its cutting edge parallel to its own axis of rotation, but the stationary blade is desirably skewed slightly relative to the rotary blade in order to cause the rotary blade to progressively engage the stationary blade from end to end. This causes the cut to be progressively eflfected, and therefore avoids the jarring effect of an instantaneous cut. The arrangement, however, involves two drawbacks. 1

It is important in envelope manufacture that each cut blank occupy a definite angular disposition at the concusion of cutting, but this is interfered with by a slight and somewhat indefinite twisting of the blank caused by the fact that the blank is severed last at one side boundary of the web. This is a very troublesome point.

It is also important that the paper be cut cleanly through from side to side, without clashing of the blades but neverthelcss with substantial contact of the blades at every point. It is a simple matter to grind the rotary blade to a straight edge and to set that edge parallel to the axis of rotation. The edge of the rotary blade is thus caused to travel in a true cylindrical path. Since the cutting edge of the stationary blade, if straight, would not extend parallel to the rotary axis of the rotary blade, it would necessarily intersect the path of the rotary blade. It is necessary to specially hone the stationary blade to make it conform to the cylindrical path of the rotary blade. The stationary blade is initially formed with a straight beveled edge, but the honing provides an arcuate boundary of increasing width from one end of the blade to the other. The greater the length of the blade, the greater will be the amount of honing required. The ratio of the amount of honing to length increases as the length increases.

The present invention eflectively avoids the twisting of the blank, and also reduces the amount of honing required.

It is a feature that instead of employing one square and one skewed blade, provision is made of one square blade (either stationary or rotary), and opposed edge either stationary or rotary, and in either case the square blade will be opposed by oppositely skewed blade segments. The skewed blade segments are caused to make a very blunt reflex angle whose vertex is disposed to engage the opposed blade first. This causes the web to be cut from the center outward, and thereby eliminates the unbalancing effect which tended to turn or twist the blanks when the cut was caused to progress from edge to edge of the web.

It is a further feature that provision is made of means. for supporting the blades and blade segments rigidly to secure them against vibration or displacement.

Other objects and advantages will hereinafter appean.

In the drawing forming part of this specification:

Fig. 1 is a diagrammatic plan view of parts of an illus-- trative flying cutter, showing a web being fed obliquely past the cutter;

Fig. 2 is a diagrammatic sectional view in elevation showing the rotary and stationary cutting means in the act of cutting an envelope blank from the leading end of the web;

Fig. 3 is a fragmentary View of the web nearly cut across, showing particularly that the opposite margins of the web are simultaneously cut through last;

Fig. 4 is a diagrammatic plan view of the cutting means, showing particularly the angular relations of the rotary cutting blade and of the stationary cutting blade segments; I

Fig. 5 is a view in elevation, partly in section, taken upon the line 5-5 of Fig. 7 looking in the direction of the arrows;

Fig. 6 is a fragmentary, sectional, detail view of a blade segment, its holder bar, and a tension screw associated with it;

Fig. 7 is a fragmentary view in elevation of the structure shown in Fig. 5, the view being taken in the direction of the arrows 7-7 of Fig. 5;

Fig. 8 is a sectional view taken upon the line 8-3 of Fig. 5, looking in the direction of the arrows;

Fig. 9 is a transverse sectional view through a second form of flying cutter, in which a single stationary blade is set square, and oppositely skewed blade segments are provided on the rotary carrier, the section being taken on the line 9-9 of Fig. 10;

Fig. 10 is a fragmentary view in elevation of the cutter of Fig. 9; and

Fig. 11 is a fragmentary plan view of the cutter of Figs. 9 and 10.

In Figs. 1 and 2, a web ll) of sheet material, suitable for the manufacture of envelopes, is drawn off a reel (not shown), around a stationary guide rod or roller 12, and between bodily fixed feed rollers 14, 16 being thrust by the feed rollers across horizontal supporting means (not shown) and between a rotary cutting blade 18 and a stationary cutting means 20 so that a blank will be severed from the leading end of the web each time that the blade 18 completes a revolution. The web is desirably ad vanced continuously at uniform speed, but in order that blanks of dilferent lengths (on a side) may be cut, provision is made for adjusting the rate of web feed as pointed out in Serial No. 344,572 filed March 25, 1953. The

rotary blade 18 is driven at uniform speed and in fixed relation to the speed of the main drive shaft, being carried by a cylinder 22 unitary with a supporting and driving shaft 24. The shaft 24 is rotatively mounted at its opposite ends between upper and lower complementary bearing members 26 and 28.. The bearing members 28 are rigidly carried by a-bar 30. The bar 30 is supported with capacity for adjustment about the axis of a vertical pivot member 32, said axis being located vertically beneath the center of the line of web cutting. The flying cutter is carried as a unit on the. bar 30 and may be adjusted angularly as a unit relative to the direction of web feeding.

The stationary cutting means 20 includes a supporting block 34 which is set in rabbets of the bearing members 26 and is secured rigidly .to the bearing members 26 by headed screws 35. The block 34 supports the other parts of the stationary cutting means. At one side the block 34 may have a plane face which is parallel to the axis of the shaft 24, but at the opposite side the block has two plane'lfaces 36 and 38 which, at the middle of :the bar, form with one another a reflex dihedral angle, desirably of substantially l82. The faces 36 and 38 control the disposition in the machine of two stationary blade segments 40 together with blade carrying bars 44 forthe respective blade segments.

Each carrying bar 44 is of inverted L-shape, having a body 48 and an angularly related head 50. Each blade segment is securely aflixed to its carrier bar by pins 52, being held securely in the angle of the carrier bar in position to receive support both from the body 48 and from the head 50.. The blade segments and their associated carrier bars have aligned slots 54 and 56, respectively,

through which the shanks of beaded screws 58 are passed. When the blade segments and carrier bars have been adjusted and made rigid through means to be. described, the screws 58 are threaded home in threaded bores of the block 34 to clamp the bars against the associated skewed faces of the block 34. The body portions of the carrier bars are of uniform thickness, and therefore the cutting edges of the stationary blade segments are caused to extend parallel to the skewed faces of the block 34, and to make equal but opposite angles of substantially 1 with the cutting edge of the rotary blade. The vertex of the reflex angle formed by the blade segments meets the rotary blade 18 first.

Before the tightening of the clamping screws 58, the stationary blade segments are adjusted and secured against vibration in position to have their inner edges ground into conforming relation to the cylindrical path of the blade 18. Head blocks 60 are secured on top of the block 34 by headed screws 62, and jut out into positions to overlie the bars and the blade segments 40.

Each block 60 has threaded through it a series of thrust block 60 up to the slot 70 and are threaded into the block beyond the slot. The screws 70 may be tightened one after another to lock the screws 64, 66 against turning. When all of the screws 64, 66 have been locked, the screws 58 are turned up tightly to lock the blade segments and their carrier bars securely against the skewed faces of the block 60.

The described assembly and adjustment may be efiected with the block 34 in place in the machine, or they may be effected in a grinding device which is substantially a duplicate of the parts shown in Fig. 5, save that a grinding wheel is substituted for the cylinder 22 and the parts carried by the cylinder. This latter procedure is preferred. With the block 34 secured by screws 35 on bearing members 26 of the grinding device the parts carried by block 34 are assembled with block 34 and adjusted and secured as described. The grinding wheel is then operated to grind the blade segments to the required cylindrical contour, and the assembly, including the blocks 34, is transferred to the machine and secured in place by the screws 35.

It is important thatthe rotary bladelS be supported firmly against local yielding. The blade 18 is set in a radial slot 72 of the cylinder 22, and is supported at intervals by screws 74 which are threaded into diametrical bores 76 of the cylinder 22.

The end screws 74 are first adjusted into light contact with the blade 18 to support the cutting edge of the blade in parallelism with the axis of the cylinder 22 and at a desired distance from such axis. Set screws 78, threaded into the cylinder at right angles to the blade 13, are then tightened against the blade to lock it in place. The remaining screws 74 are then advanced to bear firmly against the back of the blade 18. The screws 74 cannot locally distort the blade because one screw 78 is provided for each screw 74, the paired screws being disposed with their axis in a common plane.

The utilization of angularly related blade segments causes the line of cut to be deviated from a straight line. For most purposes, at least, the amount of deviation is too slight to be of any consequence. In envelope manufacturing such deviation is not material because the opposite ends of a .cut define edges of dilferent envelope flaps, and these edges are separately folded in with their respective flaps.

In Figs. 9 to 11 another flying cutter is disclosed which represents essentially a reversal of the blade arrangement disclosed in Figs. 1, 2 and 4, to 8. Web feeding means (not shown) is provided as before. In this instance a rigid, stationary, frame supported cross bar 102 has secured to it by headed screws 104 a square set, straight edged, stationary blade 1%. The blade 105 is set in screws 64 which bear downward through buttons 67 against the upper face of an associated blade carrying bar 44. As shown, there are four of these thrust screws for each blade carrying .bar. Between each two adjacent thrust screws for a bar 44, a headed tension screw 66 is passed freely downward through the block 60 and threaded into the associated carrier bar. Three tension screws are shown associated with each bar and blade segment.

With the other screws backed olf far enough to be ineffective, the end tension screws are first adjusted to locate the inner and outer extremities of the associated blade edge just in position to make contact with the rotary blade. The intermediate screws are then adjusted to fix the bar and blade rigidly in place.

When both blade segments have been thus deformed,

a continuous slot 68 which intersects allthe bores through -Headed clamping which the screws and 66 pass. screws 70 are provided at opposite sides of eachof the screws 64, 66 and pass at right anglesto the screws 64,.

66. The shanks of thes'crews 70 pass freely through the a rabbet of the bar l02, and the screws 104 have their shankspassed through slots of the blade and threaded into the bar 102. As the blade is reduced in height by successive resharpenings, shims may be inserted between the upper face of the blade and the opposed face of the bar 102. A cylinder 108, driven at constant speed, is made to carry two skewed blade segments 119. The blade segments 119 are equally but oppositely skewed. The blade segments meet one another midway between the ends of the cylinder in a reflex angle which is desirably of the order of 182. The vertex of the angle leads so that the stationary blade and the rotary blade ments cooperate to cut the web in a balanced manner from the center of the web outward. toward both side edges. As before, the cylinder and the stationary cutter support 102 form parts of a unit which is adjustable about a vertical pivot directly in line with the central point of cutting.

The cylinder is provided with a radial bore 114 midway between its ends, and with straight slots 16 whose longitudinal median planes meet substantially in the axis of the bore 114. The slots. are disposed at an angle of substantially 182 to one another. In each slot there is disposed an L-shaped carrying bar 118 for one of the blade segments 110. Each segment 110 is fixedly secured to its associated carrying bar 118 by pins 120. Tension screws 122 and thrust screws 124 are inserted in bores 126 and 128, respectively, of the cylinder 108, the e being two tension screws and two thrust screws shown as asso- *ciated with each blade segment carrying bar 113.

The tension screws are adjusted to cause the mid-points of the skewed blade segments 110 just to touch the edge of the blade 106, and the opposite ends of each biade segment to extend outward equal radial distances from the axis of the cylinder 108. The thrust screws are then adjusted to secure the blade segments against radial and longitudinal vibration. Screws 128, threaded into bores 130 of the cylinder 108, are then tightened against the blade segments 110 to clamp them firmly against trans verse vibration. When the blades 110 and their carrying bars 118 have been adjusted and secured in place as described, the cylinder is transferred to bearings of a grinding device in which a stationary grinding tool is adjustable toward and from the axis of the bearings. The cylinder is then rotated, with the grinding tool being fed gradually inward until the blade segments have been grounddown to a uniform radius equal to theradius for which the mid-points of the blade segments were set. The cylinder is then replaced in the machine ready for service.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim: a

1. A web cutting mechanism comprising, in combination, means for feeding a web along a prescribed path, and a flying cutter comprising cooperative stationary cutting means and rotary cutting means, one of said cutting means including a straight edged blade whose cutting edge is disposed parallel to the axis of rotation of the rotary cutting means, and the other including a pair of blade segments which meet centrally of the web feed path and which are oppositely skewed relative to the straight edged blade to define a blunt angle whose vertex meets the straight edged blade first, said blade segments having their cutting edges so curved that all points of said edges are equidistant from the axis of rotation of the rotary cutting means, and means supporting said flying cutter with capacity for adjustment as a unit about an axis which is at right angles to the axis of the rotary cutting means and whose prolongation substantially contains the vertex of the angle formed by the blade segments, to vary the shape of the blanks cut.

2. A web cutting mechanism comprising, in combination, means for feeding a web along a prescribed path, and a flying cutter comprising cooperative stationary cutting means and rotary cutting means, said rotary cutting means including a straight edged blade whose cutting edge is disposed parallel to the axis of rotation of the rotary cutting means, and the stationary cutting means including a pair of blade segments whose cutting edges meet centrally of the web feed path in a very blunt'angle whose vertex meets the straight edged blade first, said blade segments having all points of their cutting edges equidistant from the axis of rotation of the rotary cutting means, and means supporting said flying cutter with capacity for adjustment as a unit about an axis which is at right angles to the axis of the rotary cutting means and whose prolongation substantially contains the vertex of the angle formed by the blade segments, to vary the shape of the blanks cut.

3. A web cutting mechanism comprising, in combination, means for feeding a web along a prescribed path, and a flying cutter comprising cooperative stationary cutting means and rotary cutting means, said stationary cutting means including a straight edged blade whose cutting edge is disposed parallel to the axis of rotation of the rotary cutting means, and the rotary cutting means including a pair of blade segments which meet centrally of the web feed path and which are oppositely skewed relative to the straight edged blade to define a blunt angle whose vertex meets the straight edged blade first, said blade segments having their cutting edges so curved that all points of said edges are equidistant from the axis of rotation of the rotary cutting means, and means supporting said flying cutter with capacity for adjustment as a unit about an axis which is at right angles to the axis of the rotary cutting means and whose prolongation substantially contains the vertex of the angle formed by the blade segments, to vary the shape of the blanks cut.

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